i mentioned to my builder that I don't like it that in thailand most concrete is too wet. he said to me he could use less water but then he has to use an additive so the concrete is easier to work with. the name of the product is Sika super-1. Apparantly it also makes the concrete more dense, so stronger and more waterproof.Is this the way to go for me?

rob28 wrote:i mentioned to my builder that I don't like it that in thailand most concrete is too wet. he said to me he could use less water but then he has to use an additive so the concrete is easier to work with. the name of the product is Sika super-1. Apparantly it also makes the concrete more dense, so stronger and more waterproof.Is this the way to go for me?

What you have been told is utter BS. Please read all that has been posted exhaustively on the subject of concrete to find the answer before posting new questions (see forum instructions). Do take particular attention to the articles on slump tests, how concrete cures, and how to prevent curing problems. Do follow all the many links to outside sites with technical information. You will find additional advice on concrete, particularly waterproofing, in the section on Swimming Pools. If all else fails, I will be happy to help.

I already did some internet research . I read the sika website and found this:

Sikament® FFHigh Range Water Reducing AdmixtureDescription Sikament FF is a high range water reducing admixture.Sikament FF meets the requirements for ASTM C-494 Types A and F.Application Sikament FF is recommended for use by ready-mix and precast concrete producerswhenever the manufacture of high strength concrete products requireshigh plasticity and increased early and ultimate strengths.Advantages Water Reduction: Sikament FF allows up to 30% water reduction when usedas a high range water reducing admixture. Sikament FF delivers high strengthconcrete with increased early and ultimate compressive and flexural strengths.High Plasticity: The superplasticizing action of Sikament FF provides excellentworkability and concrete will flow easily at very low water cement ratio’s.For Precast and Architectural Concrete: Sikament FF produces fl owingconcrete that requires less vibration while delivering a fi nished product withimproved surface fi nish and overall aesthetics. Higher early strengths allowfaster demolding and more effi cient production. Sikament FF will not affect thecolor of concrete.Sikament FF reduces bug holes, and its superplasticizing action provides thefollowing benefi ts: Accelerated early strength gains allow faster demolding and more efficientuse of forms. Higher ultimate strengths for cost effective high performance concrete. Increased slump improves workability and increases labor productivity. Normal setting time even at high dosage rates. Full fl ow action aids in pumping and reduces need for vibration. Greater concrete density reduces permeability and increases durability.Sikament FF does not contain calcium chloride or any other intentionally addedchlorides and will not initiate or promote the corrosion of steel in the concrete.

I think it sounds good, make the thais use less water and get a stronger mix. they happy, me happy. or not?Rob

Concrete is stronger the less water is used. Concrete only needs to be just liquid enough to correctly fill any formork. There should be no water on the the top of freshly laid concrete, and sand and aggregate should be firm. Mixing instructions are given on every bag and one can always do a slump test. A reasonably competent labourer knows perfectly well how to mix concrete. If he suggests you need additives to correct his lack of knowledge, fire him, fast.

A reasonably competent labourer knows perfectly well how to mix concrete

I don't necessarily agree with this. I think they do have a tendency to add to much water to concrete here in certain instances. Certain applications call for serious reductions in the amount of water present, such as polished concrete counter tops. Certain additives can be used in these instances. For slabs which you want certified results you should get ready max CPAC. If requested they will have QA come out and perform a slump test, and also take a sample and perform a factory stress test which indicates the load achieved (kilograms per square centimeter).

This is not really a response, but a further question for you experts out there. I have several repair jobs that need to be done, and my question concerns the availability or otherwise in Thai stores of a concrete/mortar additive that contains PVA (polyvinyl acetate.)

The product available in the UK is Unibond, but I cannot find it here. My professional builder friend in the UK recommends its use for concrete and mortar mixes, and as a painted-on film when repairing cracks, etc. Apparently it is an excellent product.

Does anyone know if there are any equivalent products (i.e., that contain PVA) easily available in Thailand?

This is not really a response, but a further question for you experts out there. I have several repair jobs that need to be done, and my question concerns the availability or otherwise in Thai stores of a concrete/mortar additive that contains PVA (polyvinyl acetate.)

The product available in the UK is Unibond, but I cannot find it here. My professional builder friend in the UK recommends its use for concrete and mortar mixes, and as a painted-on film when repairing cracks, etc. Apparently it is an excellent product.

Does anyone know if there are any equivalent products (i.e., that contain PVA) easily available in Thailand?

PVA is a common wood and paper glue, as a painted-on film for concrete it is diluted 5 to 1 (water/PVA). As a wood worker I usually use TOA in Thailand. You will have to check the translation and there ma well be a cheeper glue in the adhesives section of Global House or your local school supplies shop etc.

A reasonably competent labourer knows perfectly well how to mix concrete

I don't necessarily agree with this. I think they do have a tendency to add to much water to concrete here in certain instances. Certain applications call for serious reductions in the amount of water present, such as polished concrete counter tops. Certain additives can be used in these instances. For slabs which you want certified results you should get ready max CPAC. If requested they will have QA come out and perform a slump test, and also take a sample and perform a factory stress test which indicates the load achieved (kilograms per square centimeter).

Nor do I agree. water reducing agents are good in most applications. Most builders, as already mentioned, will put more than enough water in the mix so the concrete levels itself without having to shovel it around, etc. Drivers of ready-mix concrete trucks will also put a lot of water so the concrete flows real nice out of the shoot without having to drag it out with a shovel......slump tests and cylinder tests are fine although it takes 28 days for concrete to reach it's intended strength (typically 2800 psi - compressive strength) although it keeps getting stronger long after. In the states Calcium Chloride is commonly added to concrete for speeding up the process, especially in cold climates, you wouldn't want to use it here. There are many additives now available in Thailand that didn't used to be so there's no excuse not to use them. One important reason for using them is: the cement in Thailand is Type 1, Type II is plastic cement that is more or less waterproof and stronger due to the plastic helping to bond the cement together.

The methods for concrete & tile are quite a bit different here and care should be taken to avoid having to tear it out and re-do it....

DocTom wrote:This is not really a response, but a further question for you experts out there. I have several repair jobs that need to be done, and my question concerns the availability or otherwise in Thai stores of a concrete/mortar additive that contains PVA (polyvinyl acetate.)

The product available in the UK is Unibond, but I cannot find it here. My professional builder friend in the UK recommends its use for concrete and mortar mixes, and as a painted-on film when repairing cracks, etc. Apparently it is an excellent product.

Does anyone know if there are any equivalent products (i.e., that contain PVA) easily available in Thailand?

There are much better additives available than using wood glue. Sika makes some very good products...